$a{x}^2+bx+c=0ax^2+bx+c=0$

$x_{\mathrm{1,2}}={\displaystyle \frac{-b\pm \sqrt{b^2-4ac}}{2a}}x\_\{1\{,\}2\}=\backslash dfrac\{-b\backslash pm\backslash sqrt\{b^2-4ac\}\}\{2a\}$

$2x^2+x-10=02x^2+x-10=0$

$\Rightarrow \backslash Rightarrow$ $a=2a=2$; $b=1b=1$; $c=-10c=-10$

$x_{\mathrm{1,2}}={\displaystyle \frac{-1\pm \sqrt{(1{)}^2-4\cdot 2\cdot (-10)}}{2\cdot 2}}x\_\{1\{,\}2\}=\backslash dfrac\{-1\backslash pm\backslash sqrt\{(1)^2-4\backslash cdot\; 2\backslash cdot\; (-10)\}\}\{2\backslash cdot\; 2\}$

$x_{\mathrm{1,2}}={\displaystyle \frac{-1\pm \sqrt{1+80}}{4}}x\_\{1\{,\}2\}=\backslash dfrac\{-1\backslash pm\backslash sqrt\{1+80\}\}\{4\}$

$x_{\mathrm{1,2}}={\displaystyle \frac{-1\pm 9}{4}}x\_\{1\{,\}2\}=\backslash dfrac\{-1\backslash pm9\}\{4\}$

$x_1=2x\_1=2$; $x_2=-\mathrm{2,5}x\_2=-2\{,\}5$